Oxyfuel process is the most applied industrial thermal cutting process for cutting several metals. It can cut thickness from 0.5 mm to 1000 mm or more, the equipment required is low cost and can be used manually or mechanized. Oxyfuel is the mixture of oxygen and a fuel gas such as acetylene, propane, propylene, or natural gas. Oxyfuel process cuts metals by means of the chemical reaction of oxygen with the base metal at elevated temperature. Oxyfuel is used to preheat the metal to its ‘ignition’ temperature (for steel, it is 700-900° C.) which is well below its melting point. A jet of pure oxygen is then directed into the preheated area initiating a vigorous exothermic chemical reaction between the oxygen and the metal to form metal oxide or slag. The oxygen jet blows away the slag enabling the jet of oxygen to pierce through the material and continue to cut through the material.
Due to its high flame temperature and cutting speed, oxyacetylene flame has long been used for cutting and welding purposes by metal fabricators. Further, acetylene has the highest primary Btu emission and the greatest combustion velocity than commonly available fuel gases. It rapidly heats the base metal up to the kindling point. Other fuel cutting or welding fuel gases are propane, propylene, natural gas, etc. However, the flame temperatures produced by these fuels (in oxygen) are substantially lower compared to acetylene. For example, the maximum flame temperature for propane and natural gas in oxygen is approximately 2810° C. and 2770° C. respectively compared to maximum flame temperature of 3160° C. with acetylene.
The principal torch gas used therefore has been acetylene which is expensive, difficult to store and transport and requires the use of almost pure oxygen for cutting ferrous metals and forms persistently adherent slag. Back firing tendency is another problem often faced while using oxyacetylene flame. As acetylene explodes when subjected to very high pressures, oxyacetylene flame cannot be used under deep water at depths greater than 20 feet under water.
A number of attempts have been made to improve torch gas used in cutting and/or welding torches by adding an additive or additives to them. U.S. Pat. No. 5,236,467 discloses use of methyl ethyl ketone and methyl terbutyl ether in an amount of 0.5% to 13%, preferably 5% to 8% of the base hydrocarbon by weight for use as torch gas. U.S. Pat. No. 3,591,355 proposes the addition of liquid alkanol such as methanol and a mixture of alkanes such as pentane and isopentane, while U.S. Pat. No. 3,989,479 discloses the addition of methanol.
Chinese Patent CN1253167 uses propane, butane & propylene as base gas with combustion aid solution consisting of mixture of KMnO4, H2O2 and NaHCO2 and containing one oily component which contains 1-3 g ferrocene per 100 ml of gasoline. In another Patent CN 1297024, ferrocene 100-500 g, barium dialkylphenolate (alkylphenolate), iso propane 1-7 L and benzene for preparation of industrial fuel gas have been used for welding applications. British Patent Specification No. 813981 discloses the use of an oxygen containing compound such as isoprypyl ether, methyl isopropyl ether, methyl propyl ether and methanol.
None of the disclosures in the prior art disclose a composition which can result in reduced consumption of fuel or oxygen.
In view of the aforementioned attempts and their limitations the present invention discloses improved hydrocarbon fuel compositions which reduce consumption of expensive fuel or oxygen.